Switch and operating mechanism therefor



March 13, 1934. R. A. NORLING 1,951,033

SWITCH AND OPERATING MECHANISM THEREFOR Filed Dec. 8, 1932 ATTORNEY? Patented Mar. 13, 1934 UNITED STATES PATENT OFFICE SWITCH AND OPERATING MECHANISM THEREFOR Application December 8, 1932, Serial No. 646,231

11 Claims.

This invention relates to a switch device and operating mechanism therefor for portable electric tools.

4 The general purpose and object of my invention is to provide a switch device and operating means therefor of a character usable with one of the handles of the tool and having a control member which forms all or a part of the grasp- I ing portion of the handle, whereby the switch may be readily and easily controlled by that hand of the operator supporting the tool at such handle.

Another object of my invention is to provide the control member in the form of a sleeve rotatably mounted on the exterior of the handle, whereby the operator may control the switch by merely rotating his hand about the axis of the handle without releasing his supporting grip thereon.

A further object of my invention is to provide spring means in the switch actuating means for automatically opening the switch and returning the control member to switch open position upon the release of the control member, thereby equipping the tool with a safety device which immediately stops the tool upon the release of the switch.

A further object of my invention is to provide the connection between the control member and the switch actuating mechanism in the form of cam means which serves to open and close the switch upon the rotation of the control means.

A further object of my invention is to provide a rugged and strong, yet simple and inexpensive switch means and actuating mechanism therefor, particularly adaptable for portable electric tools, such as drills and the like, and moreover to so house or enclose the parts of the switch means and actuating devices to keep them free of dirt and dust and contact with outside objects, except the control sleeve, which in the manner of its mounting and operation is not capable of accidental movement.

The invention consists further in the matters hereinafter described and claimed.

In the accompanying drawing:-

Fig. 1 is a side view of an electric drill provided with a switch and switch handle of my invention;

Fig. 2 is a longitudinal sectional view through the switch and switch handle, the switch being shown in closed position in full lines and in open position in dotted lines; and

Figs.- 3 and 4 are transverse sectional views taken on lines 3--3 and 4-4, respectively, of Fig. 2.

The drill shown in the drawing has side handles 1, 2 on opposite sides of its outer casing. The handles extend laterally outward from the casing and provide grasping portions on opposite sides of the tool, whereby the latter may be held in both hands of the operator when in use. The section 3 or" the outer casing contains the electric motor for rotating the spindle 4 of the tool. The spindles projects out of the outer casing at its gear case section 5 and is connected with the motor through a reducing gear assembly in said section as in tools of the character herein shown. The portion of the spindle accessible from the exterior of the tool is constructed to receive and hold the drill bit or other working element 6 for the tool.

The switch for turning on and off the electric current to the motor of the tool is of the quick make and break type and is located in the switch case 7, which in the particular tool shown, is arranged between the motor case 3 and the handle 2. The switch may be of any desired construction, a rotative snap type being illustrated in the drawing and comprising movable contacts 8, 8 rotatable about an axial support 9 into and out of engagement with fixed contacts 10, 10. The switch assembly is supported in the case '7 from a fibre or other insulating plate 11, through which the leads from the electric cable 12 extend. The switch case '7 is bolted or otherwise secured to the motor case 3, there being a connecting opening between them so that certain of the leads from the cable may extend to the motor, as shown in Fig. 2. The cable is fastened to the switch case cover 13 which is bolted or otherwise secured to the switch case over the plate 11 as shown.

The handle 2 comprises a tubular or hollow stem fitting in a recess or socket in the switch case '7 and secured therein in any preferred manher, as by a screw 14 shown in Fig. 2. Arranged within the handle 2 and extending lengthwise thereof is an endwise movable element or rod 15 about which is a tension coil spring 15 having its opposite ends engaging abutments, the one 1'? being on the rod and the other 18 being the end wall of the socket in which the handle stem is fitted. The rod 15 extends through this wall into the switch case 7 and is there provided with a slot or recess 19 to connect the rod with an operating arm 20 of the switch mechanism as shown.

The opposite end of the rod 15 is rigidly connected as by a pin 21, to a member in the form of a cam sleeve 22 slidably mounted in the handle 2 adjacent its outer end and held from rotation therein by a cross-pin 23 extending through a longitudinal slot 24 in the sleeve as shown in Fig. 2. Pin 23 extends across the interior of the handle stem 2 and has its ends fitting in apertures 25, 25 in the surrounding wall of the stem as shown in Fig. 3. The pin is held in place by having its ends overlapped by a sleeve 26 rotatably mounted on the exterior of the stem 2.

Sleeve 22 is provided with a cam slot 2'7 spirally disposed with respect to the axis of the sleeve and extending entirely through the same. A pin 28 extends through the slot and is connected with the handle sleeve 26 by having its ends fitted in apertures 29, 29 therein as shown in Fig. 4. Thus the pin will be turned bodily about the axis of the stem 2 upon the rotation of the handle sleeve. With the pin operating in the cam slot 27, the cam sleeve 22 and connected rod 15 will be moved endwise in the rotation of the handle sleeve. The pin 28 as shown in Fig. 4, extends through radial slots 30, 30 in the handle stem 2 and thus is held from movement axially of the handle stem. With the pin connected with the handle sleeve, the latter is held from axial displacement on the handle stem 2. The extreme outer end or" the stem 2 is closed by a cover or cap 31 having screw threaded connection with the stem 2 and overlapping the adjacent end of the handle sleeve 26 and the outer ends of the pin 28.

, The switch mechanism shown and described, operates as follows:

The switch is shown in closed position in full lines in Fig. 2, at which time it is necessary for the operator to hold the handle sleeve 26 against rotation, due, to the fact that the spring 16 being under compression will automatically disconnect the switch on release of the handle sleeve. When the latter is released, the spring expands and moves the rod 15 and connected cam sleeve 22 toward the outer end of the handle stem 2, thereby opening the switch by moving the arm 20 thereof into the position shown in dotted lines in Fig. 2. This of course moves the contact members 8 out of engagement with the contact members 10 as shown. This positions the pin 28 at the inner end of the cam slot 2'7 as is apparent. To close the switch, the handle sleeve 26 is turned or rotated to the right in the form of structure shown in the drawing, and the cam slot 27 acting on the pin 28 will move the cam sleeve 22 and rod 15 inward to close the switch through its arm 20. This inward movement of the rod will compress the spring 16 against the socket wall 17 and place the spring under tension to automatically open the switch when the handle sleeve is released. I could, of course, omit the spring, in which event the switch would remain in either closed or open positions and remain in these positions until changed by turning the handle sleeve.

The spring, however, is a safety factor, making the switch a self opening one and requiring the operator to turn'the handle sleeve into switch closing position and hold it in that position to keep the tool in operation. With the switch opening automatically when the handle sleeve is released, no opportunity is afiorded for keeping the tool in operation when not desired, as when withdrawing the tool from the work and when moving it from place to place-while connected with the source of power. Moreover, with the cam means returning the handle sleeve to its normal position when released, the switch cannot be accidentally closed on handling the tool as the handle sleeve must be forcibly turned against the tension of the spring to close the switch.

In addition to the safety factor as provided by the spring, the advantages of the. construction shown and described are as follows. The switch handle and the switch mechanism are imple and rugged in construction. The mechanism is dust and dirt proof in that all of the parts are enclosed in the casings provided therefor. There are no protruding parts or levers,

thus avoiding the necessity of any holes or slots open at all times to admit dust and dirt to interfere with the operation of the switch or its actuating means. The latter being carried by and incorporated in one of the tool handles and having its control member in the form of a sleeve surrounding the handle and rotatable thereon, enables the operator to grasp the handle through the sleeve and control the operation of the tool without releasing this grasp on the handle or changing the position of his hand with respect thereto except to turn the sleeve the slight extent necessary to close the switch. With the sleeve rotatable and held in normal position by the spring, no opportunity is afforded to accidently close the switch should exterior objects contact-with the sleeve when dragging the tool over an underlying surface or when moving the tool from place to place. Moreover, the handle sleeve or control member for the switch embracing the handle stem and movable axially thereof provides the grasping portion for the stem and thus is the part held by the operator in supporting the tool when in use.

The switch handle shown and described can be readily and easily assembled and disassembled. In disassembling, the switch cover 13 is removed and the switch lifted off of the rod 15. The cap 31 is then unscrewed by hand and the pin 28 will slip out and the handle sleeve 26 will slip off the handle stem 2. This uncovers the pin 23, which will slip out of the slot 24, and rod 15 will slip out of the open outer end of the stem 2. It is obvious that the parts may be readily assembled, both the assembling and disassembling of the same being accomplished with no other tools than a screw driver for releasing the switch cover 13.

If a different length of switch handle is desired, all that is required isto shorten or lengthen the handle stem 2 and rod 15, the rest of the structure remaining unchanged.

The details of construction and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and scope of my invention, except as pointed out in the appended claims.

I claim as my invention:

1. In a portable electric tool having a casing containing a motor for operating the tool, a tool handle carried by the casing and extending outwardly therefrom, a switch for the tool motor, an actuating mechanism for the switch carried by the tool handle, a control member for the actuating mechanism, said control member being movably mounted on the tool handle and embracing the same, and cam means within the tool handle connecting the control member with the actuating mechanisni'for operating the switch through the movement of the control member on the handle.

2. In a portable electric tool having a casing containing a motor foroperating the tool, a hollow tool handle carried by the casing and. extending outwardly therefrom, a switch for the tool motor, an actuating mechanism for the switch within the handle, a sleeve rotatably mounted on the handle, and cam means connecting the sleeve with the actuating mechanism through the handle intermediate the ends thereof for operating the switch on turning the sleeve.

3. In a portable electric tool having a casing containing a motor for operating the tool, a tool handle carried by the casing and extending outwardly therefrom, a switch for the tool motor, an actuating mechanism for the switch carried by the tool handle, a control member for the actuating mechanism, said control member being movably mounted on the tool handle and embracing the same, cam means within the tool handle connecting the control member with the actuating mechanism for operating the switch through the movement of the control member on the handle, and spring means included in the actuating mechanism for automatically opening the switch and returning the member to switch open position upon the release of the same.

4. A switch device of the character described, comprising a switch and a casing therefor, a tubular handle stem carried by the casing and extending outwardly therefrom, an actuating mechanism for the switch within the stem and completely housed thereby, a sleeve rotatably mounted on the stem, means connecting the actuating mechanism with the sleeve through an opening on the stem for operating the switch on turning the sleeve, said sleeve encircling the stem and closing said opening, and means closing the opposite ends of the stem.

5. In a portable electric tool having a motor for operating the same, a tool handle carried by the casing of the tool and extending outwardly therefrom, a switch for the motor of the tool, an endwise movable member carried by the tool handle and connected with the switch for operating the same, a sleeve rotatably mounted on the tool handle, and means providing a connection between the sleeve and said member for imparting endwise movement thereto to actuate the switch upon the rotation of said sleeve.

6. In a portable electric tool having a motor for operating the same, a tool handle carried by the casing of the tool and extending outwardly therefrom, an endwise movable member carried by the tool handle and connected with the switch for operating the same, a sleeve rotatably mounted on the tool handle, and cam means connecting the sleeve to the member whereby endwise movement will be imparted to the member to actuate the switch upon the rotation of said sleeve.

7. In a portable electric tool having a motor for operating the same, a hollow tool handle carried by the casing of the tool and extending outwardly therefrom, a switch for the motor of the tool, a rod and a connected member slidably mounted within the tool handle and engageable with the switch for operating same, a sleeve rotatably mounted on the exterior of the tool handle, and means providing a pin and cam slot connection between the sleeve and said member for imparting endwise movement thereto to actuate the switch upon the rotation of said sleeve.

8. A switch actuating device of the character described, comprising a switch casing with a switch therein, a tubular handle stem carried by the casing and extending outwardly therefrom, a rod and connected member slidably mounted in said stem for operating the switch, a sleeve rotatably mounted on said stem, a cam slot in said member, a pin extending through said slot and connected with said sleeve for imparting endwise movement to said member upon the turning of the sleeve, and a radial slot in the stem through which the pin extends to hold the pin against movement with the member, but permitting movement of the pin with the sleeve on the turning of the same.

9. A switch device of the character described, comprising a switch casing having a switch therein, a tubular handle stem carried by the switch casing and extending outwardly therefrom, a rod slidably mounted in said stem and connected with the switch for operating the same, a pair of sleeves supported by the stem, one within the stem and the other on the outer side of the same, the inner sleeve being connected with the rod for movement therewith and having slots therein, one extending longitudinally of the sleeve and the other angularly with respect to the axis thereof, pins extending through said slots, the pin extending through the longitudinal slot having its ends connected with the stem and the pin extending through the cam slot having its ends connected with the outer sleeve, the latter extending over the outer ends of the first mentioned pin for holding the same in place and rotatable on the stem for imparting endwise movement to the rod and connected inner sleeve, and a cap member fitted over the outer end of the stem and extending over the rotatable sleeve to hold the other pin in place.

10. A switch device of the character described, comprising a switch and a casing therefor having a socket, a tubular handle stem fitted in said socket and extending outwardly therefrom, a rod slidably mounted in said stem and extending into the switch case through the socket for actuating the switch, a sleeve rotatably mounted on said stem, means providing a connection between the sleeve and the rod for imparting endwise movement thereto on turning the sleeve, and a coil spring about the rod and acting thereon to be compressed on closing the switch and to automatically open the switch through the rod on the release of the sleeve.

11. A switch device of the character described, comprising a switch and a casing therefor, a tubular handle stem carried by said casing and extending outwardly therefrom, the inner end of the stem being closed by the casing, an operating mechanism for the switch carried by the stem and completely enclosed therein, a control member for the operating mechanism in the form of a sleeve rotatably mounted on the stem, means connecting the operating mechanism with the sleeve through the stem intermediate the ends thereof, said sleeve encircling the stem and enclosing the connecting means, and a cap closing the outer end of the stem and the sleeve.

REINI-IOLD A. NORLING. 

